Washing machines

ABSTRACT

A washing machine may comprise a cabinet; a first tub fixedly mounted in an inside of the cabinet and configured to accommodate wash water; a second tub configured to accommodate laundry and rotatably mounted inside of the first tub; a drive motor mounted outside of the first tub and configured to rotate the second tub; a driving circuit unit connected with the drive motor so as to apply a driving signal to the drive motor; and/or a water-cooling cooler unit configured to cool the drive motor and the drive circuit unit with the wash water accommodated in the first tub.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application claims priority from Korean Patent Application No. 10-2013-0006068, filed on Jan. 18, 2013, in the Korean Intellectual Property Office (KIPO), the entire contents of which are incorporated herein by reference.

BACKGROUND

1. Field

Some example embodiments may relate to washing machines. Some example embodiments may relate to washing machines capable of reducing washing time.

2. Description of Related Art

In general, a washing machine is a machine that launders laundry by the physical action of water streams and the chemical action of detergent. The washing machine may be classified as a vertical type washing machine, in which a wash tub is vertically mounted, and a drum type washing machine, in which the wash tub is horizontally or slopingly mounted, depending on the type of mounting of the wash tub spinning the laundry.

These washing machines commonly include a drive motor spinning the wash tub and a drive circuit applying a driving signal to the drive motor. In the drive motor and the drive circuit, an overheating phenomenon may happen due to continuous operations in the processes of washing, rinsing, and dehydrating. As a result, a pause time for halting the operation of the drive motor and the drive circuit is required to cool the drive motor and the drive circuit, resulting in an increase in a total washing time.

SUMMARY

Some example embodiments may provide washing machines that may minimize pause times so as to prevent overheating of drive motors and/or drive circuits.

Some example embodiments may provide washing machines that may reduce power consumption by heaters when wash water is heated.

In some example embodiments, a washing machine may comprise a cabinet; a first tub fixedly mounted in an inside of the cabinet and configured to accommodate wash water; a second tub configured to accommodate laundry and rotatably mounted inside of the first tub; a drive motor mounted outside of the first tub and configured to rotate the second tub; a driving circuit unit connected with the drive motor so as to apply a driving signal to the drive motor; and/or a water-cooling cooler unit configured to cool the drive motor and the drive circuit unit with the wash water accommodated in the first tub.

In some example embodiments, the water-cooling cooler unit may comprise a first cooling channel configured to cool the drive motor and/or a second cooling channel connected with the first cooling channel and configured to cool the drive circuit unit.

In some example embodiments, the drive circuit unit may comprise a drive circuit board applying the driving signal to the drive motor; and/or a radiator member irradiating heat of the drive circuit board.

In some example embodiments, the first cooling channel may have a structure surrounding a circumference of the drive motor.

In some example embodiments, a first end of the second cooling channel may be connected with the first cooling channel. A second end of the second cooling channel may be connected with the radiator member.

In some example embodiments, a through hole may be formed in the radiator member so as to penetrate an inside of the radiator member. The second end of the second cooling channel is connected with the through hole.

In some example embodiments, at least an inside of the first cooling channel may be formed of thermal conductive material.

In some example embodiments, the washing machine may further comprise a first connector between the first tub and the water-cooling cooler unit. The first connector may be configured to deliver the wash water accommodated in the first tub to the water-cooling cooler unit.

In some example embodiments, the first connector may be connected with a filter configured to filter out impurities contained in the wash water.

In some example embodiments, the washing machine may further comprise a drainage unit mounted on a bottom of the first tub to discharge the wash water accommodated in the first tub to an outside of the cabinet.

In some example embodiments, a first end of the first connector may be connected with the drainage unit. A second end of the first connector may be connected with the water-cooling cooler unit.

In some example embodiments, the wash water received through the first connector may be heated in the water-cooling cooler unit by the drive motor and the drive circuit unit.

In some example embodiments, the wash water heated in the water-cooling cooler unit may be resupplied to the fixed tub.

In some example embodiments, the washing machine may further comprise a second connector between the water-cooling cooler unit and the first tub. The second connector may be configured to deliver the wash water heated in the water-cooling cooler unit to the first tub.

In some example embodiments, the second connector may be connected with a bottom of the first tub.

In some example embodiments, the washing machine may further comprise a housing configured to accommodate the drive motor, the driving circuit unit, and the water-cooling cooler unit. The housing may comprise insulating material.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and/or other aspects and advantages will become more apparent and more readily appreciated from the following detailed description of example embodiments, taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a schematic view of a washing machine according to some example embodiments;

FIG. 2 is a schematic view illustrating an example of a water-cooling cooler unit of FIG. 1;

FIG. 3 is a schematic view of a washing machine according to some example embodiments; and

FIG. 4 is a schematic view illustrating an example of a water-cooling cooler unit of FIG. 3.

DETAILED DESCRIPTION

Example embodiments will now be described more fully with reference to the accompanying drawings. Embodiments, however, may be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these example embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope to those skilled in the art. In the drawings, the thicknesses of layers and regions may be exaggerated for clarity.

It will be understood that when an element is referred to as being “on,” “connected to,” “electrically connected to,” or “coupled to” to another component, it may be directly on, connected to, electrically connected to, or coupled to the other component or intervening components may be present. In contrast, when a component is referred to as being “directly on,” “directly connected to,” “directly electrically connected to,” or “directly coupled to” another component, there are no intervening components present. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.

It will be understood that although the terms first, second, third, etc., may be used herein to describe various elements, components, regions, layers, and/or sections, these elements, components, regions, layers, and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer, and/or section from another element, component, region, layer, and/or section. For example, a first element, component, region, layer, and/or section could be termed a second element, component, region, layer, and/or section without departing from the teachings of example embodiments.

Spatially relative terms, such as “beneath,” “below,” “lower,” “above,” “upper,” and the like may be used herein for ease of description to describe the relationship of one component and/or feature to another component and/or feature, or other component(s) and/or feature(s), as illustrated in the drawings. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of example embodiments. As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises,” “comprising,” “includes,” and/or “including,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

Example embodiments may be described herein with reference to cross-sectional illustrations that are schematic illustrations of idealized example embodiments (and intermediate structures). As such, variations from the shapes of the illustrations as a result, for example, of manufacturing techniques and/or tolerances, are to be expected. Thus, example embodiments should not be construed as limited to the particular shapes of regions illustrated herein but are to include deviations in shapes that result, for example, from manufacturing. For example, an implanted region illustrated as a rectangle will typically have rounded or curved features and/or a gradient of implant concentration at its edges rather than a binary change from implanted to non-implanted region. Likewise, a buried region formed by implantation may result in some implantation in the region between the buried region and the surface through which the implantation takes place. Thus, the regions illustrated in the figures are schematic in nature, their shapes are not intended to illustrate the actual shape of a region of a device, and their shapes are not intended to limit the scope of the example embodiments.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which example embodiments belong. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and should not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

Reference will now be made to example embodiments, which are illustrated in the accompanying drawings, wherein like reference numerals may refer to like components throughout.

FIG. 1 is a schematic view of a washing machine 1 a according to some example embodiments. FIG. 2 is a schematic view illustrating an example of a water-cooling cooler unit 100 a of FIG. 1.

Referring to FIG. 1, the washing machine 1 a includes a cabinet 10 forming the exterior, a fixed tub 20 fixedly mounted in the inside of the cabinet 10, a wash tub 30 rotatably mounted in the fixed tub 20, a drive motor 40 rotating the wash tub 30, a drive circuit unit 50 applying a driving signal to the drive motor 40.

An inlet 11 is formed in the front portion of the cabinet 10 so as to put laundry into the inside of the wash tub 30, wherein the inlet 11 is opened and closed by a door 12 mounted in the front portion of the cabinet 10. A door glass 13 formed of a transparent material may be mounted in the door 12 so that users may see the state of the inside of the wash tub 30 with the naked eye.

An opening 21 is formed at a position corresponding to the inlet 11 of the cabinet 10 in the front portion of the fixed tub 20. A gasket 22 connecting the inlet 11 and the opening 21 may be mounted between the inlet 11 of the cabinet 10 and the opening 21 of the fixed tub 20 so as to shield a space formed between the inlet 11 of the cabinet 10 and the opening 21 of the fixed tub 20. The gasket 22 may be formed of an elastic material in order to respond to vibration of the fixed tub 20. A heater 23 may be placed in the inside of the fixed tub 20. For example, the heater 23 may be placed on the inner surface of the bottom of the fixed tub 20. Wash water accommodated in the inside of the fixed tub 20 may be heated by the heater 23.

A water supply unit 60 is mounted at an upper portion of the fixed tub 20 so as to supply wash water into the fixed tub 20. The water supply unit 60 is connected with an external water supply source (not shown) and a detergent supply device 70. The detergent supply device 70 is connected with the fixed tub 20 through a connecting hose 61. The wash water supplied through the water supply unit 60 may be supplied to the inside of the fixed tub 20 with detergent via the detergent supply device 70.

A drainage unit 80 is mounted at a lower portion of the fixed tub 20 so as to discharge the wash water from the inside of the fixed tub 20 to the outside of the cabinet 10. A first drain pipe 81, a filter 83, a drain pump 84, and a second drain pipe 82 are mounted in the drainage unit 80. The filter 83 may have a detachable structure.

The wash tub 30 may include a cylindrical portion 31, a front plate 32 placed at a front side of the cylindrical portion 31, and a rear plate 33 placed at the back side of the cylindrical portion 31. An opening 32 a through which laundry is inserted and drawn out is formed in the front plate 32, and a rotating shaft 34 that receives power from the drive motor 40 is connected in the rear plate 33.

A plurality of a through holes 35 are formed in the circumference of the wash tub 30 for a flow of the wash water, and a plurality of lifters 36 are mounted on the inner circumferential surface of the wash tub 30 so that laundry may rise and fall when the wash tub 30 is rotated.

The drive motor 40 is mounted on the outside of the fixed tub 20. For example, the drive motor 40 may be fixedly mounted at a lower portion of the outer side of the fixed tub 20 by a support 41. A drive shaft 42 of the drive motor 40 delivers power to the rotating shaft 34 of the wash tub 30 by a power transmission unit 43. When the drive shaft 42 of the drive motor 40 rotates, the rotating shaft 34 connected with the drive shaft 42 rotates, and accordingly, the wash tub 30 rotates around the rotating shaft 34. In the drive motor 40, the rotating direction and rotating speed of the wash tub 30 vary with the drive signal received from the drive circuit unit 50.

The drive circuit unit 50 is connected with the drive motor 40. The drive circuit unit 50 may include a drive circuit board 51 (see FIG. 2) applying a driving signal to the drive motor 40, and a radiator member 53 (see FIG. 2) absorbing heat of the drive circuit board 51 and radiating the heat. The drive circuit board 51 may be a Printed Board Assembly (PBA) including a rectifier that converts commercial Alternating Current (AC) power to Direct Current (DC) power, and an inverter that converts the DC power to motor drive power. The radiator member 53 may be a metallic heat sink. Although it is not shown in the drawing, the washing machine 1 a may include a display circuit unit that controls a display displaying washing time, etc., and an electric device circuit unit that controls electric device components. The display circuit unit and the electric device circuit unit may be spaced apart from the drive circuit unit 50, or integrated on a single circuit board as necessary.

During washing and rinsing, the drive motor 40 rotates at a low speed forward and backward. Contaminants are removed from the laundry while the laundry repeatedly rises up and falls down in the inside of the wash tub 30 by rotation of the wash tub 30. During dehydrating, when the drive motor 40 rotates the wash tub 30 in one direction at a high speed, water is separated from the laundry by centrifugal force.

Thus, power is supplied to the drive motor 40 rotating the wash tub 30 and the drive circuit board 51 applying the driving signal to the drive motor 40 in the processes of washing, rinsing, and dehydrating in the washing machine 1 a. The power is supplied to the drive motor 40 and the drive circuit board 51, and therefore the temperatures of the drive motor 40 and the drive circuit board 51 increase. Although the temperature rise of the drive circuit board 51 may be somewhat reduced by the radiator member 53, the cooling rate of the radiator member 53 has limits due to constraints such as the size and material of the radiator member 53. Thus, in the case that the drive motor 40 and the drive circuit board 51 continuously operate for a desired time (that may or may not be predetermined) or more without a separate cooling process, the drive motor 40 and the drive circuit board 51 overheat, and thus the drive motor 40 or the drive circuit board 51 may cause a damage or a malfunction. For example, in the case that the temperature of the drive motor 40 exceeds about 110° C. to about 130° C. or the temperature of the drive circuit board 51 exceeds about 80° C. to about 90° C., the drive motor 40 or the drive circuit board 51 may cause a damage or a malfunction. In order to prevent the drive motor 40 or the drive circuit board 51 from causing damage or a malfunction, overheating of the drive motor 40 or the drive circuit board 51 needs to be prevented. As one of these methods, a method of allowing a pause time of stopping operation of the drive motor 40 or the drive circuit board 51 may be adopted, but in the case of stopping the operation of the drive motor 40 or the drive circuit board 51 without a separate cooling process, the pause time may be increased, and accordingly, the total washing time may be increased.

In some example embodiments, provided is the water-cooling cooler unit 100 a cooling the drive motor 40 and the drive circuit unit 50 with water. Because the water-cooling cooler unit 100 a cools not only the drive motor 40 but also the drive circuit unit 50, overheating of the drive motor 40 and the drive circuit unit 50 is prevented at the same time. If the water-cooling cooler unit 100 a is a structure cooling only one of the drive motor 40 and the drive circuit unit 50, overheating of the other one may not be prevented. As a result, it may be difficult to reduce the pause time. For example, in the case that the water-cooling cooler unit 100 a cools only the drive motor 40, overheating of the drive circuit unit 50 may not be prevented. In this case, the pause time may be required to prevent overheating of the drive circuit unit 50. Meanwhile, in the case that the water-cooling cooler unit 100 a cools only the drive circuit unit 50, overheating of the drive motor 40 may not be prevented. In this case, the pause time may be required to prevent overheating of the drive motor 40. However, because the water-cooling cooler unit 100 a according to some example embodiments has a structure cooling both the drive motor 40 and the drive circuit unit 50 together by water, the pause time may be omitted or minimized so as to prevent overheating of the drive circuit unit 50 and the drive motor 40. As a result, the total washing time including washing, rinsing, and dehydrating of the washing machine 1 a may be shortened.

The drive motor 40 and the drive circuit unit 50 may be placed adjacently in order to minimize the size of the water-cooling cooler unit 100 a. As an example, the drive circuit unit 50 may be fixed on one side of the drive motor 40.

The water-cooling cooler unit 100 a cools the drive motor 40 and the drive circuit unit 50 with the wash water contained in the fixed tub 20. The wash water contained in the fixed tub 20 is supplied to the water-cooling cooler unit 100 a, and then the wash water supplied to the water-cooling cooler unit 100 a absorbs heat of a relatively high temperature of the drive motor 40 and the drive circuit unit 50. In other words, heat exchange occurs between a high temperature of the drive motor 40 and the drive circuit unit 50 and a low temperature of the wash water, and thus the drive motor 40 and the drive circuit unit 50 are cooled and the wash water is heated. Because the water-cooling cooler unit 100 a adopts a structure using the wash water as a coolant, without addition of a separate configuration for coolant supply, the drive motor 40 and the drive circuit unit 50 may be cooled with a simple structure.

A first connector 110 a may be placed between the water-cooling cooler unit 100 a and the fixed tub 20, in order to deliver the wash water accommodated in the fixed tub 20 to the water-cooling cooler unit 100 a. One end of the first connector 110 a is directly connected with the fixed tub 20, or may be indirectly connected with the fixed tub 20 via the drainage unit 80 mounted on the lower portion of the fixed tub 20.

As an example that the first connector 110 a is indirectly connected with the fixed tub 20, one end of the first connector 110 a may be connected with the filter 83 of the drainage unit 80, as shown in the drawing. The filter 83 may filter out impurities (or contaminants) contained in the wash water supplied to the first connector 110 a. The filter 83 prevents the impurities from moving to the first connector 110 a, thereby preventing the water-cooling cooler unit 100 a from being blocked by the impurities. A circulation pump 114 a may be connected with the first connector 110 a. The circulation pump 114 a makes the wash water move to the water-cooling cooler unit 100 a. The driving force of the circulation pump 114 a may be adjusted by considering the flow resistance of the first connector 110 a and a second connector 120 a which will be described later, and the height of the wash water accommodated in the fixed tub 20.

Referring to FIG. 2, the water-cooling cooler unit 100 a supplies the wash water through an inlet 103 a, and discharges the wash water through an outlet 104 a. The inlet 103 a is connected with the first connector 110 a, and the outlet 104 a is connected with the second connector 120 a. The water-cooling cooler unit 100 a includes a first cooling channel 101 cooling the drive motor 40 with the wash water supplied through the inlet 103 a, and a second cooling channel 102 cooling the drive circuit unit 50 and connected with the first cooling channel 101.

The first cooling channel 101 has a structure surrounding the circumference of the drive motor 40. For example, the first cooling channel 101 may have a hollow cylindrical structure, and the drive motor 40 may be placed in the hollow of the first cooling channel 101. Because the temperature of the wash water flowing through the first cooling channel 101 is lower than the temperature of the drive motor 40, and the wash water flows through the first cooling channel 101 surrounding the drive motor 40, heat exchange occurs between the wash water flowing through the first cooling channel 101 and the drive motor 40. Through this heat exchange, overheating of the drive motor 40 may be prevented. The inner wall of the first cooling channel 101 may be made of a thermal conductive material so that heat exchange actively occurs between the drive motor 40 and the wash water. The thermal conductive material includes materials with excellent thermal conductivity, such as aluminum or copper.

The second cooling channel 102 cools the drive circuit unit 50. To do so, the second cooling channel 102 may cool the radiator member 53, which is one of the components of the drive circuit unit 50. As the radiator member 53 is cooled, the drive circuit board 51 connected with the radiator member 53 may be cooled. The second cooling channel 102 is placed so as to contact the radiator member 53, and the wash water flowing through the second cooling channel 102 may penetrate the radiator member 53. The second cooling channel 102 may be connected with a through hole 53 a formed through the inside of the radiator member 53. Accordingly, the wash water supplied through the second cooling channel 102 may pass through the through hole 53 a. Heat exchange occurs between the wash water passing through the through hole 53 a and the radiator member 53, and thus, the radiator member 53 may be cooled. Due to the cooling of the radiator member 53, overheating of the drive circuit board 51 may be prevented. The second cooling channel 102 connects the first cooling channel 101 with the through hole 53 a of the radiator member 53. To this end, one end of the second cooling channel 102 is connected with the first cooling channel 101, and the other end thereof is connected with the through hole 53 a of the radiator member 53. A flexible material, for example, a rubber hose may be used as the second cooling channel 102. By utilizing a flexible material as the second cooling channel 102, the first cooling channel 101 and the through hole 53 a of the radiator member 53, which are differently disposed and oriented, may easily be connected to each other. One through hole 53 a is shown in the drawing, but example embodiments are not limited thereto, and as a plurality of through holes may be formed.

Connection gaskets G1 and G2 may be placed between the first cooling channel 101 and the second cooling channel 102, and the second cooling channel 102 and the radiator member 53. Through the connection gaskets G1 and G2, the wash water may be prevented from leaking from a connection portion between the first cooling channel 101 and the second cooling channel 102, and a connection portion between the second cooling channel 102 and the radiator member 53.

A housing 130 accommodates the drive motor 40, the drive circuit unit 50, and the water-cooling cooler unit 100 a therein, and may prevent penetration of water or moisture from the outside of the housing 130.

Referring back to FIG. 1, the water-cooling cooler unit 100 a may resupply the wash water heated by the drive motor 40 and the drive circuit unit 50 to the fixed tub 20. Accordingly, the power consumption of the heater 23 heating the wash water may be reduced.

During a process of washing or rinsing, the heater 23 heats the wash water contained in the fixed tub 20 up to a desired temperature (that may or may not be predetermined). In some example embodiments, in order to reduce the power consumption of the heater 23 heating the wash water, the waste heat that unintentionally occurs in the course of operations of the drive motor 40 and the drive circuit unit 50, may be recycled. In other words, the drive motor 40 and the drive circuit unit 50 may be used as an auxiliary heating unit of the wash water.

A second connector 120 a may be placed between the water-cooling cooler unit 100 a and the fixed tub 20. The second connector 120 a connects the outlet 104 a of the water-cooling cooler unit 100 a with the fixed tub 20. The wash water discharged through the outlet 104 a (see FIG. 2) is delivered to the fixed tub 20 through the second connector 120 a. At this point in time, the circulation pump 114 a makes the wash water heated in the water-cooling cooler unit 100 a move toward the fixed tub 20.

The second connector 120 a may be connected on the bottom of the fixed tub 20. As the second connector 120 a is connected on the bottom of the fixed tub 20, the length of the second connector 120 a may be shortened more than a case that the second connector 120 a is connected with the side of the fixed tub 20. By shortening the length of the second connector 120 a, a structure of the second connector 120 a may be simplified, and simultaneously a lowering of the temperature, which may occur while the heated wash water flows through the second connector 120 a, may be reduced.

An insulating member may be arranged on the outside of the second connector 120 a, although it is not shown in the drawing. As the insulating member prevents heat exchange between the wash water and the external portion of the insulating member, the lowering of the temperature of the wash water may be reduced while the wash water passes through the second connector 120 a.

The housing 130 accommodating the water-cooling cooler unit 100 a may be formed of an insulating material. Accordingly, the lowering of the temperature of the wash water flowing through the water-cooling cooler unit 100 a may be prevented due to blocking heat exchange with the outside of the housing 130 by using the insulating material. In addition, the housing 130 may be formed of a fire-resistant material in order to prevent damage due to heat of the drive motor 40 and the drive circuit board 51.

FIG. 3 is a schematic view of a washing machine 1 b according to some example embodiments, and FIG. 4 shows an example of the water-cooling cooler unit 100 b of FIG. 3. A description of components that have the same reference numerals in FIGS. 1 and 2 is omitted. Below, only the differences between example embodiments of FIGS. 3 and 4 and that of FIGS. 1 and 2 are described.

Referring to FIGS. 3 and 4, in order to deliver wash water accommodated in a fixed tub 20 to a water-cooling cooler unit 100 b, a first connector 110 b may be placed between the water-cooling cooler unit 100 b and the fixed tub 20. The first connector 110 b may be indirectly connected with a drainage unit 80 mounted on the bottom of the fixed tub 20. As an example where the first connector 110 b is indirectly connected with the fixed tub 20, the first connector 110 b may be branched from a first drain pipe 81 of the drainage unit 80. As an example, one end of the first connector 110 b may be connected with the upper portion of the first drain pipe 81. The other end of the first connector 110 b may be connected with the upper portion of the water-cooling cooler unit 100 b. The other end of the first connector 110 b may be connected with an inlet 103 b of the water-cooling cooler unit 100 b.

A second connector 120 b may be placed between the water-cooling cooler unit 100 b and the fixed tub 20. One end of the second connector 120 b is connected with an outlet 104 b of the water-cooling cooler unit 100 b, and the other end thereof may be connected on the bottom of the fixed tub 20. A circulation pump 114 b is placed in the second connector 120 b, and thus the wash water heated in the water-cooling cooler unit 100 b may be moved toward the fixed tub 20. The positions of the inlet 103 b and the outlet 104 b may be changed depending on the need.

On the following, the operating processes of the washing machines 1 a and 1 b according to some example embodiments will be described.

A water supply unit 60 mounted on the upper portion of the fixed tub 20 supplies wash water to the fixed tub 20. At least some of the wash water supplied through the water supply unit 60 is supplied to the inside of the fixed tub 20 with detergent via a detergent supply device 70. The wash water flows from the inside of the wash tub 30 to its outside, or from the outside of the wash tub 30 to its inside, through the plurality of through holes 35 formed in the wash tub 30.

The drive motor 40 is rotated by the drive signal applied by the drive circuit unit 50. The drive motor 40 rotates, and thus the wash tub 30 connected with the drive motor 40 and the power transmission unit 43 is rotated. When the wash tub 30 is rotated, laundry repeatedly rises up and falls down by a lifter 36 mounted on the inner circumferential surface of the wash tub 30.

While the drive motor 40 rotates, at least some of the wash water accommodated in the inside of the fixed tub 20 is delivered to the water-cooling cooler unit 100 a or 100 b through the first connector 110 a or 110 b. While the wash water flows through the inside of the water-cooling cooler unit 100 a or 100 b, heat exchange occurs between the drive motor 40 and the drive circuit unit 50. The drive motor 40 and the drive circuit unit 50 are cooled and the wash water is heated through the heat exchange. The wash water heated is resupplied to the fixed tub 20 through the second connector 120 a or 120 b. Because the wash water resupplied to the fixed tub 20 is in a heated state, power consumption is reduced in order to heat the wash water by the heater 23. The wash water may be moved from the fixed tub 20 to the water-cooling cooler unit 100 a or 100 b through the first connector 110 a or 110 b, or from the water-cooling cooler unit 100 a or 100 b to the fixed tub 20 through the second connector 120 a or 120 b by the circulation pump 114 a or 114 b. The filter 83 is connected with and mounted on the first connector 110 a and thus impurities contained in the wash water may be removed before the wash water is supplied to the water-cooling cooler unit 100 a.

Table 1 below shows the results of performing washing and rinsing processes using a washing machine (comparative example 1) that does not include a water-cooling cooler unit 100 a and the washing machine 1 a (embodiment 1) including the water-cooling cooler unit 100 a of FIG. 1.

Power of about 200 W is supplied to each of the drive circuit units 50 of the washing machines according to comparative example 1 and embodiment 1, and a net operation time of the wash tub 30 is set to about 169 minutes for washing and rinsing processes.

TABLE 1 Power con- Net Total sumption operation consumed Running (W) time (Min) time (Min) ratio Com- Input of 200 169 206 0.82 parative drive example 1 circuit unit Loss of 20 169 206 0.82 drive circuit unit Input of 180 169 206 0.82 drive motor Loss of 72 169 206 0.82 drive motor Embodi- Input of 200 169 174 0.97 ment 1 drive circuit unit Loss of 20 169 174 0.97 drive circuit unit Input of 180 169 174 0.97 drive motor Loss of 72 169 174 0.97 drive motor

Referring to Table 1, the total consumed time was measured to be about 206 minutes for washing and rinsing processes of the washing machine according to the comparative example 1, and the total consumed time was measured to be about 174 minutes for washing and rinsing processes of the washing machine 1 a according to the embodiment 1. When the measured results are analyzed, a running ratio, which is a ratio of the net operation time of the wash tub 30 to the total consumed time of washing and rinsing processes, is about 0.82 for the comparative example 1 and is about 0.97 for embodiment 1. In other words, a pause time caused by overheating of comparative example 1 is about 18%, whereas the pause time caused by overheating of embodiment 1 is decreased to about 3%. About 3% of the pause time is the time required to change the rotation direction of the wash tub 30 to prevent tangling of the laundry, that is to say, the time required to stop rotating and change the rotating direction. As described above, by using the water-cooling cooler unit 100 a using wash water, the pause time is reduced by about 15%, and thus the water-cooling cooler unit 100 a provides an effect of reducing the total washing time.

Referring to Table 1, in the processes of washing and rinsing, about 20 W that is about 10 percent of electric power supplied to the drive circuit unit 50 is lost and about 72 W that is about 40 percent of electric power supplied to the drive motor 40 is lost, commonly in embodiment 1 and comparative example 1. Most of the lost electric power is converted into heat. Since the water-cooling cooler unit 100 a is not included in comparative example 1, heat of the drive motor 40 and the drive circuit unit 50 have not been used, but since the wash water flowing in the water-cooling cooler unit 100 a is resupplied to the fixed tub 20 in embodiment 1, heat of the drive circuit unit 50 and the drive motor 40 may be absorbed. Accordingly, to heat the wash water in comparative example 1, the heater 23 used electric energy of about 333 Wh (Watt-hours), whereas in embodiment 1 the heater 23 used electric energy of about 172 Wh. In other words, the amount of power consumed by the heater 23 was able to be lowered by about 48%. In embodiment 1, the heat corresponding to the remaining electric energy of about 160 Wh may be obtained through the water-cooling cooler unit 100 a, and this is electric power that the wash water flowing through the water-cooling cooler unit 100 a obtained from the drive circuit unit 50 and the drive motor 40 during the total consumed time of washing and rinsing processes.

As described above, according to some example embodiments, they should be interpreted as the specific example embodiment illustrated, rather than to limit the scope of the disclosure. For example, in some example embodiments, the drum washing machines 1 a and 1 b have been described, but they are only exemplary illustrations, and may also be modified into a vertical type washing machine in which a wash tub 30 is vertically mounted. Meanwhile, it will be understood by a person having ordinary skill in the art (PHOSITA) to which example embodiments pertain, that the structure of the washing machines 1 a and 1 b may be modified in various forms. Therefore, the scope of this disclosure is not determined by the example embodiments described, but shall be determined by technical ideas listed in the scope of the patent claims.

It should be understood that the exemplary embodiments described therein should be considered in a descriptive sense only and not for purposes of limitation. Descriptions of features or aspects within each embodiment should typically be considered as available for other similar features or aspects in other embodiments. 

What is claimed is:
 1. A washing machine, comprising: a cabinet; a first tub fixedly mounted in an inside of the cabinet and configured to accommodate wash water; a second tub configured to accommodate laundry and rotatably mounted inside of the first tub; a drive motor mounted outside of the first tub and configured to rotate the second tub; a driving circuit unit connected with the drive motor so as to apply a driving signal to the drive motor; and a water-cooling cooler unit configured to cool the drive motor and the drive circuit unit with the wash water accommodated in the first tub.
 2. The washing machine of claim 1, wherein the water-cooling cooler unit comprises: a first cooling channel configured to cool the drive motor; and a second cooling channel connected with the first cooling channel and configured to cool the drive circuit unit.
 3. The washing machine of claim 2, wherein the drive circuit unit comprises: a drive circuit board applying the driving signal to the drive motor; and a radiator member irradiating heat of the drive circuit board.
 4. The washing machine of claim 2, wherein the first cooling channel has a structure surrounding a circumference of the drive motor.
 5. The washing machine of claim 3, wherein a first end of the second cooling channel is connected with the first cooling channel, and wherein a second end of the second cooling channel is connected with the radiator member.
 6. The washing machine of claim 5, wherein a through hole is formed in the radiator member so as to penetrate an inside of the radiator member, and wherein the second end of the second cooling channel is connected with the through hole.
 7. The washing machine of claim 2, wherein at least an inside of the first cooling channel is formed of thermal conductive material.
 8. The washing machine of claim 1, further comprising: a first connector between the first tub and the water-cooling cooler unit; wherein the first connector is configured to deliver the wash water accommodated in the first tub to the water-cooling cooler unit.
 9. The washing machine of claim 8, wherein the first connector is connected with a filter configured to filter out impurities contained in the wash water.
 10. The washing machine of claim 8, further comprising: a drainage unit mounted on a bottom of the first tub to discharge the wash water accommodated in the first tub to an outside of the cabinet.
 11. The washing machine of claim 10, wherein a first end of the first connector is connected with the drainage unit, and wherein a second end of the first connector is connected with the water-cooling cooler unit.
 12. The washing machine of claim 8, wherein the wash water received through the first connector is heated in the water-cooling cooler unit by the drive motor and the drive circuit unit.
 13. The washing machine of claim 12, wherein the wash water heated in the water-cooling cooler unit is resupplied to the fixed tub.
 14. The washing machine of claim 12, further comprising: a second connector between the water-cooling cooler unit and the first tub; wherein the second connector is configured to deliver the wash water heated in the water-cooling cooler unit to the first tub.
 15. The washing machine of claim 14, wherein the second connector is connected with a bottom of the first tub.
 16. The washing machine of claim 1, further comprising: a housing configured to accommodate the drive motor, the driving circuit unit, and the water-cooling cooler unit; wherein the housing comprises insulating material. 